PAGASA: PH experiencing start of southwest monsoon, but not onset of rainy season

May 24, 2017 - 2:33 PM
Vehicles and commuters are stranded in Las Pinas due to flooding and heavy rain brought by the southwest monsoon (habagat) in this August 2013 file photo. iNTERAKSYON FILE PHOTO

MANILA – The country is experiencing the start of the southwest monsoon, although it is not yet the onset of the rainy season.

In a press conference on Wednesday, the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) said the southwest monsoon was still at a weak stage (compared to moderate and strong), and this was marked by an intensity of wind ranging from 20 kph to 30 kph.

PAGASA Weather Forecasting Section chief Robert Sawi said that another indicator of the start of the southwest monsoon were the early morning or afternoon rainshowers and thunderstorms, which the country had been experiencing for the past few days. It would also likely experience the same in the following days.

PAGASA Climate Monitoring and Prediction Section officer-in-charge Analiza Solis explained that PAGASA hadn’t declared the onset of the rainy season yet because some indicators had not yet been seen.

The onset of the rainy season is marked by the start of a five-day period – usually in April, May, June, or July – with a total rainfall of 25 millimeters or more, with three consecutive days having at least one millimeter of rainfall per day.

Based on PAGASA’s rainfall monitoring, the country had “way below to below normal rainfall conditions” from May 1 to 23. This meant that despite the rain, the Philippines was still experiencing less than it should be.

Solis said the onset of the rainy season would commence between May 28 to June 8, “plus or minus two days”. The usual onset of the rainy season in the Philippines is on May 27 and June 5.